Method of forming piston rings



EETHOD OF FO RMING PISTON RINGS Filed Sept. 5, 1935 W, iyamoa BY 7M'1 ATTORN EY I in speed, highcompression engines,

8% point of the mentalities of which atented Septo i4, 193'? amazes William Wuertel,

George Kessier,

Appiication September 3 @iaims.

The object of my present invention is to devise a novel method of and apparatus for forming piston rings.

In the manufacture of piston rings it has been customary to so construct the piston ringthat it would have uniform radial pressure. It has bmn iound recently that piston rings with uniform radial pressure'have a tendency to flutter at the ends near the gap. In the modern high this fluttering to blow by the ention permits theburned gases rings to such an extent that the rings are burned.

Piston ring manufacturers are now experiie menting to produce a piston ring that has a greater unit pressure at the gap than at other points of its circumference. This is a dimcult problem because no point of the circumference can be oi minus pressure. This means that the 2d piston ring must be light tight.

With the above in view, my invention comprehends a novel method of and apparatus for forming piston rings which will produce the form or shape necessary to provide the desired pressures 25 for modern engines. I

It further comprehends a. novel method of and apparatus for forming piston rings wherein by changing the dimensions of the difierent components of the apparatus, the pressure at any circumference of the ring can be varied.

Other novel features of construction and advantage will hereinafter more clearly appear in the detailed description and the appended claims.

For the purpose of I have shown in the accompanying drawing a typical embodiment of it, hich, in practice, will give satisfactory and reliable results. It is, however, to be understood that the various instrumy invention consists can be variously arranged and organized, and my invention is not ted to the exact arrangement and organizationbf these instrumentalitiem as 4 5 herein set forth. a

Figure 1 is a top plan viewof an apparatus which may be advantageously employed in carrying out my method, and illustrated in conjunction with a piston ring.

Figure 2 is a top plan view of the apparatus.

Figure 3 is a side elevation of the apparatus with the piston rings in place.

Figure 4 is a side elevation of the apparatus.

Figure'5 is a top plan view of a finished piston illustrating the invention,

or G rrsron Wits Phiiadciphia, Pa, assignor to :4. delphia, 2 a.

3, 1935, neriai No, 3%,951

(Ci. Big-21.5)

Figure 6 is a top plan view of a split piston ring before being placed on the former.

Similar numerals indicate corresponding Referring to the drawing:

Referring first to Figures 2 and 4, the apparatus comprehends a form 5, which acts as a spreader, and which is turned down to provide a. cylindrical forming surface 2 and an annular shoulder 3. i is a spacer or spreader adjustably connected to the body portion by a fastening device 5, such as a bolt and nut, so as to provide for the use of spacers or spreaders of difierent widths.

t designates the piston, rings which are to be formed, in accordance with my present invention, and which are in the form of cylindrical split rings. y

In carrying out my novel method, the piston rings are mounted on the form, as shown in Figures 1 and. 3, and the spacer determined gap between the free ends of the rings. The rings while on the form, are heated to a suitable temperature for the proper length of time depending on the character of material used in making the rings. After the rings have been heated, they may be left to cool in the atmosphere or they may be quenched. Piston rings made by this method have the desired form in a. pressure gage. The important component parts are a form and a spacer or spreader. Each of these have a definite effect on the form of the finished ring. To increase the rounclness of the width of the spreader 4. To increase the plus pressure at the gap I increase the diameter of the form. This variation can be kept to very close limits in either direction depending upon the result desired. The rings produced by this method can be grooved, channeled, slotted or drilled and still be held to the desired or predetermined form or contour. In this manner, piston rings which are dished, or which have been subjected to special operations can be produced without materially changing their form. If it is found that any previous or future operation afiects the form of the finished piston ring, it can be corrected by varying the components of the former.

It will be apparent from the-foregoing, that in accordance with this invention, one is enabled ,-to produce a piston ring which will have the reparts.

quisite form or shape to give the pressures desired for modern engines.

In Figure 5, I have shown a piston ring in detached position, to indicate more clearly the gap which is produced and maintained during the heat treatment. It is to be understood that this 6 forms a prenew and useful method 01' and apparatus i'or torming piston rings which embodies thei'eatures of advantage enumerated as desirable in the state ment or the invention and the above description, and while I have, in the present instance, shown and described a preferred embodiment thereof which will give in practice satisfactory and reliable results, it is to be understood that this embodiment is susceptible to modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described my invention, whatil claim' as new and desire to secure by Letters Patent is:-

1. The method of forming a piston ring, which consists in stretching a split ring over a spreader with a gap former between the iree ends of the ring and with the free ends of the ring exerting a I pressure against opposite sides of the gap i'ormer,

amazes and with the free ends .0! the ring and diametrically opposite portions 01' the ring exerting pressure against the spreader, and subjecting the ring in such conditionto heat treatment to produce a formed ring having plus pressure. at the gap.

2. The method oi iorming a pistonring which consists in stretching a split, ring over a spreader to increase the width of the ring between the free ends and opposite portions oi the ring, and having the free ends 01' the ring exerting a pressure against opposite sides of a gap former, with only the free end portions and opposite portions thereto or the ring exerting a pressure against the spread er, and subjecting the ring while in such shape on the spreader to heat treatment to produce a ring having plus pressure at the gap.

3. The method 01 forming a piston ring. which consists in stretching a split piston ring over a spreader of a width relative to the free ends of the ring and portions of the ring opposite thereto which will define a determined plus pressure at the gap 01' the ring, at the same time exerting pressure of the free ends of the ring against a gap former 01' a width to give a determined roundness or the ring, and subjecting the ring while in such shape on the iormer, to heat treatment to produce a piston ring havinga predetermined roundnqsl; and having predetermined plus pressure atthe .gap.

. WILLIAM WUERI 'IL. 

